Healthy Living: November 21, 2017

Following the first published series of hemorrhagic occlusive retinal vasculitis (HORV), the American Society of Cataract and Refractive Surgery (ASCRS) and the American Society of Retina Specialists (ASRS) formed a joint task force to further analyze the prevalence, potential etiology, treatment, and outcomes of this complication associated with intraocular surgery. In addition to the first six cases reported they have identified at least 16 additional cases of HORV for a total of 22 cases. Fourteen cases were bilateral and eight were unilateral, for a total of 36 eyes. Twelve of the cases occurred in 2015-2016, 5 cases occurred in 2013-2014, and the other 5 cases were prior to 2013. The age range was 51-84 (mean 68 years). Although reporting and data collection are ongoing, preliminary findings from these 22 cases warrant this special clinical alert because of their potential impact on patient safety. Visual outcomes were often poor; 22/36 eyes (61%) were 20/200 or worse, and 8/36 eyes (22%) were NLP. Notably, 7 of 36 eyes (19%) received an additional bolus of intravitreal vancomycin for treatment of presumed bacterial endophthalmitis. These patients had particularly poor outcomes and 5/7 eyes were NLP at most recent follow-up.

HORV Characteristic Findings:
· Occurs after intraocular procedure with normal undilated exam on postop day 1
· Delayed onset of sudden painless decreased vision (Range 1-26 days postop; mean 8 days)
· Visual acuity often poor on presentation, but may be normal in mild cases
· Mild to moderate anterior chamber and vitreous inflammation, with no hypopyon
· Sectoral intraretinal hemorrhage in areas of non-perfusion (often along venules)
· Peripheral retinal involvement in all cases, with macular ischemia and whitening in advanced disease
· Sectoral retinal vasculitis and retinal vascular occlusion on FA, corresponding to areas of hemorrhage
· Rapid progression to neovascular glaucoma common (53%)
HORV is different from ischemic CRVO, which is unilateral, usually presents on postop day 1 when associated with cataract surgery, and is associated with diffuse small intraretinal hemorrhages; conversely, HORV is often bilateral, has a delayed onset, and often presents with large patches of intraretinal hemorrhage only in sectors of retinal vascular occlusion. CME and severe vascular dilation and tortuosity are key features with CRVO, but not HORV, and the rates of NLP vision and of neovascular glaucoma are higher with HORV. Consulted immunology experts hypothesize that this might represent a rare Type III hypersensitivity reaction to vancomycin, rather than direct drug toxicity. This might be similar to leukocytoclastic vasculitis and Henoch-Schonlein purpura, which are type III hypersensitivity reactions in the skin that have also been rarely associated with vancomycin. Unfortunately, there is no current method to test for such hypersensitivity either pre- or post- HORV diagnosis.Fourteen of the 22 cases (64%) were bilateral. Because of the delayed onset, HORV did not appear in the first eye until after surgery in the second eye in the 11 cases who underwent sequential bilateral cataract surgery (3 days to 3 weeks apart). In most of these 11 sequential bilateral cases, the first eye became symptomatic first, but bilateral HORV was diagnosed simultaneously during the initial examination. Even with a long delay between eyes in the remaining 3 bilateral cases (9 months, 3 years, and 9 years) the second eye presented similarly to the first after the second eye underwent surgery.

Recommendations for Management of HORV:
· Consider avoiding intravitreal vancomycin if both bacterial endophthalmitis and HORV are in the differential.
· Consider ocular and/or systemic work-up for other syndromes (e.g. viral retinitis).
· Aggressive systemic and topical corticosteroids; consider peri- or intra-ocular steroids
· Early anti-VEGF treatment
· Early panretinal photocoagulation
Source: America Society of Cataract and Refractive Surgery